<!DOCTYPE html>
<html lang="en" xmlns:v-on="">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

    <div id="app">
        <h1>当前计数：{{counter}}</h1>
<!--        <button v-on:click="counter++">+</button>-->
<!--        <button v-on:click="counter&#45;&#45;">-</button>-->
            <button v-on:click="add">+</button>
            <button v-on:click="sub">-</button>
    </div>

    <script src="../js/vue.js"></script>
    <script>
        const  app = new Vue({
            el:'#app',
            data:{
                counter:0,
            },
            methods:{
                add: function (){
                    this.counter++
                },
                sub: function (){
                    this.counter--
                }
            }
        })

    </script>

</body>
</html>